The present invention relates to liquid dispensers and cap valve assemblies for dispensing a controlled dose of liquid. In particular, the invention relates to liquid dispensers and cap valve assemblies especially suited for dispensing liquid soaps and lotions.
Known liquid dispensers typically comprise a storage container, a housing in which the storage container is mounted, a cap valve assembly attached to the storage container, and a valve actuator. There are many applications for a liquid dispenser that can dispense a controlled amount of liquid. For example, it is convenient to use such a dispenser for liquid hand soap in a rest room. Ordinarily, the hand soap dispenser is installed on a wall of the rest room, and users can receive a desired amount of hand soap by moving the attached actuator, e.g., a lever, a button, or the like. In a different environment, the dispenser may also be utilized to dispense condiments, e.g., ketchup or mustard.
The basic structure of a liquid dispensing cap valve assembly comprising a resilient dosing reservoir and a pair of oppositely acting check valves is known in the art. One known type of liquid dispensing valve assembly has a dosing cap having an open end securable on a storage container, resilient reservoir walls, and a dispensing orifice. See U.S. Pat. No. 3,828,985 (Schindler). In one embodiment, the cap may be integrally molded as a single piece. However, the valve assembly disclosed in the Schindler patent has a spring loaded disk for opening and closing a passageway for liquid to flow out of the orifice. The valve also has an upper check valve comprising a sealing element loosely fitted in an aperture of an inlet orifice, for allowing a liquid to flow from the storage container and into the dosing reservoir. Similar to the Schindler patent, the Burd U.S. Pat. No. 4,978,036 discloses a lower check valve with a spring-loaded ball. An upper check valve of the Burd patent comprises a resilient sealing flap or a floating ball.
The cap valves of the Schindler and Burd patents have numerous operative parts. The Schindler valve assembly has at least six parts. Specifically, the Schindler valve assembly in FIG. 2 comprises retaining clapper 2, spring 3, a retaining disk 5, separating member 6, valve body 16, and apertured disk 20. The Burd valve assembly includes six parts: cylindrical wall 147, nozzle assembly 151, second check valve means 167, bias spring 173, planer member 150, and valve means 163. See FIG. 10 of the Burd patent. Needless to say, assembling a large number of parts is laborious and drives up the manufacturing cost. Additionally, the valve assemblies as in the Schindler and Burd patents may be unsuited for recycling because the assemblies include a spring, which is typically made of metal, thus requiring a sort of the metal piece from plastic pieces.
Another known type of valve assembly, produced by Stockhausen, Inc., of Greensboro, N.C., uses a resilient sealing disk mounted on a pedestal movable within a cylinder, in place of a spring-loaded disk and resilient reservoir walls. In this arrangement, the down stroke of the sealing disk creates vacuum within the cylinder reservoir to draw liquid into the reservoir. On the other hand, the up stroke of the sealing disk generates pressure within the reservoir. The pressure causes the circumferential edges of the sealing disk to deform away from the cylinder walls, creating a passageway and allowing the liquid to be dispensed. Although this type of valve assembly does not demand as many parts as the spring-loaded valve types, abrasion due to the sliding action of the disk edges against the cylinder walls may result in a loss of the seal rendering the valve partially or wholly in operative. Moreover, the valve might not smoothly operate, or become jammed in the cylinder due to residue from the dispensed liquid or imperfect sizing of the parts.
Known mechanisms for actuating cap valve assemblies include an actuator, such as a pivotable lever arm, attached to a liquid dispensing cap valve assembly. In some arrangements, the liquid is dispensed when the actuator is pulled towards the user. In other arrangements, liquid is dispensed by pushing a lever. Because personal and market preferences between the two types of actuators varies, a liquid dispenser having versatility to readily switch between both types of dispensing action, without any change of parts would be desirable.